N-Screens Problem is a set of challenges you come across when you develop an App for multiple connected devices. How HTML5 WebApp solution was the most promising solution for the developers. My session was around the 7 Key implementation challenges you will face when developing a Web App solution for multiple devices with different form factors.

The 7 key challenges were, Feature Detection, Layout detection, Using CSS3, Choice of Animation between SVG, Canvas, CSS3 Animation, and WebGL, Audio Video related problems and their work-arounds, and how to use advanced HTML5 API with a brief on Polyfills and Shims.

Here is the online demo of my presentation. Source code is also available at the demo page. Detect your N-device HTML5 features and APIs at

http://widgets-gadgets.com/html5

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Everything you need to know about developing HTML5 Apps on multiple devices is at W3C conference.
http://www.w3.org/conf/
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Redmond, Nov 15-16, 2011, amazing conference, first time all the vendors together, instead of talks about individual device/ browsers, all the sessions were focused on the common part, the HTML5 part. If you missed the conference check videos here

This is my plan for next 30 minutesI am going to talk about the N Screens we are discussing here. Then I will talk about the Design Problem for these N-Screens, By design problems I mean the difference in the context in which these screens devices are used. Then I will discuss the development problems you might face when creating apps for these devices. Particulary I will talk about two prominent ways to develop on these devices and talk about the Pros and Cons of them, and then we will see Why WebApp is the positive story every developer is talking about. Then I am going dive into technical Implementation Problems and how to solve them

- The Context - How to develop Apps for N-screens - Why the HTML5/ WebApp Solution - What are 8 Key Challenges - Where to look for latest specifications W3 Working Groups

We are talking about these 4 types of devices. A Smartphone with an advanced browser A tablet device A PC and a TV There are two things common in all these devicesThey are all Connected to the internetWe can develop Apps for each of them

- The Context - How to develop Apps for N-screens - Why the HTML5/ WebApp Solution - What are 8 Key Challenges - Where to look for latest specifications W3 Working Groups

- The Context - How to develop Apps for N-screens - Why the HTML5/ WebApp Solution - What are 8 Key Challenges - Where to look for latest specifications W3 Working Groups

W3C: Original specification

HTML can be unanimously credited for the success of the World Wide Web. The ease of the simple text based markup language, made the html pages very easy to learn, and so very popular. HTML5 Web Apps are meant for mobile devices but it is the result of five major phases of the web evolution. The “old” Web Web ApplicationsRich Internet ApplicationsHTML5 specification Mobile Web RevolutionThe “Old” WebHTML started as simple web pages development. A basic set of HTML tags were available for rendering tables, images, anchors, etc. in a web page. The HTML page is rendered in the browser sandbox and could not access user’s computer. A simple light weight text files, called Cookies were used to save user’s session information in the form of key value pairs. HTML also allowed including CSS (cascading style sheets) files for separating style from the structure and included a Scripting language, JavaScript for basic programming on the client sideWeb ApplicationsWith the popularity of the web, a more robust distributed application framework started called web applications. These web applications used a client-server architecture, where client side technologies like HTML, CSS and JavaScript were used for programming the front end, and the heavy lifting was done at the server side. HTML was still the “thin” client with the minimal access to the computer. A Rich set of programming languages like Java, PHP, and ASP were used at the server side. These server programs generated HTML pages which are emitted to the user’s browser. The server programming language could access data on the server and can do advance functionality but client side programming was limited to basic scripting like form validations.Rich Internet ApplicationsAs the web evolved the need for richer functionality like 3D, animations, web camera integration and data access grew and, web browser extensions like XPCOM and ActiveX object technologies like Adobe Flash, Java Applet and Microsoft Silverlight became popular. These technologies provided rich islands of functionalities and are also referred as Rich Internet Applications. ActiveX technology was also used for Media players and animated advertisements. Adobe Flash and Microsoft Silverlight objects in the HTML page had bigger storage in the client computer, and could access computers audio and video hardware. Browser extension technology XPCOM allows accessing computer functionality and data through a native dynamic link library.HTML5 Specification While the web was evolving with standardization of CSS and JavaScript in different types of browser, W3C and other companies came together and based on the all the previous usage and requirements of the web, created a specification for the next version of HTML, called HTML5 with a rich set of capabilities. HTML5 had a number of advanced tags for drawing, media player capabilities, content structuring tags and validation in HTML. It also had a local database with bigger Web storage options without the need of an embedded Object. It gave offline Web Application, Geo location and multi threads functionality. It also had Web sockets for peer to peer communications. The CSS3 specification supported by HTML5 included an advanced CSS effects, transitions and animations.Mobile Revolution While HTML5 specification was being created, simultaneously there was a mobile revolution, which started with the advent of advanced smartphones like iPhone, Android, and MeeGo devices. With the need of web on the mobile browser a new paradigm shift took place. There was a demand for accessing device capabilities from the web browser. The device access events and APIs started becoming a standard of its own. Device APIS like Touch and Gesture Events, Capture API for Audio, Video and Webcam captures, Contacts API, Calendar API, Web Notification, Device Status and Battery consumption, Device Orientation, etc. became a part of HTML5 specifications. These advanced APIs together with CSS3 gave birth to a new kind of application called Web Apps. Web AppsA Web App is a web application hosted in a remote server but which look, feel and behave like a native mobile application.

- The Context - How to develop Apps for N-screens - Why the HTML5/ WebApp Solution - What are 8 Key Challenges - Where to look for latest specifications W3 Working Groups

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- The Context - How to develop Apps for N-screens - Why the HTML5/ WebApp Solution - What are 8 Key Challenges - Where to look for latest specifications W3 Working Groups